Bourkes Melting

Does anyone know at what temperature Bourkes melt? I know the "HIGH" temp bourkes are heat resistant up to 500 degrees. We're trying to find out what temperature the standard Morning Pride Bourkes melt at. We had a training fire and melted 10 sets of bourkes. But mine and one other pair didn't even get blackened. We didn't have the dept issued morning pride bourkes but we also can't tell who manufactured the good ones.
Thanks

I think Bourkes are pretty much useless melted or not. It doesn't take much to get them dirty, and they do a poor job of protecting your eyes. I use goggles that cover my eyes comepletely if I need to protect my eyes. I protect the goggles with a Nomex cover.

Yep, you are required to use safety glasses or goggles with a face shield anyway, so I just keep a pair of safety glasses in my radio pocket. Besides melted bourkes look cool.

Having watched way more than one firefighter intentionally get up into the heat in a burn room to get that cool toasted helmet look (including some instructors who should know better) I'm guessing that is really the issue you are having rather than a specific brand.